but over the years on "lockup," we filmed almost every type of religion there is. and yet, still, on a standard cell search, we found out behind bars, few things are sacred. >> even though they have their bible or koran, whatever religious preference they are, they'll still hide dope in it, and hide weapons in it. you'll find razor blades and dope stuffed in the bindings. everybody finds god in prison. if you're looking for him, this is where he's at. you know, come on in. >> we've met some inmates that have seemed very devout, even as they grapple with the realities of spare their crimes. ♪ >> it was in the middle of central california we heard the sounds of the muslim call to prayer emanating from a cell at kern valley state prison. cellmates jose garza and rehan ali bhutto explain to our crew how their religious practices aren't hindered by prison bars. >> at 5:00 we come up and do prayers. we begin our day like that. >> talk to me guys, why this cell is so different from the other cells you've been in. >> islam is based on cleanness. we have to be clean. we k